/**
 * Copyright 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @flow
 * @providesModule getComponentName
 */

'use strict';

import type { ReactInstance } from 'ReactInstanceType';
import type { Fiber } from 'ReactFiber';

function getComponentName(instanceOrFiber : ReactInstance | Fiber) : string | null {
  if (__DEV__) {
    if (typeof instanceOrFiber.getName === 'function') {
      // Stack reconciler
      const instance = ((instanceOrFiber : any) : ReactInstance);
      return instance.getName() || 'Component';
    }
    if (typeof instanceOrFiber.tag === 'number') {
      // Fiber reconciler
      const fiber = ((instanceOrFiber : any) : Fiber);
      const {type} = fiber;
      if (typeof type === 'string') {
        return type;
      }
      if (typeof type === 'function') {
        return type.displayName || type.name || null;
      }
    }
  }
  return null;
}

module.exports = getComponentName;
